JPH05118751A - Method and apparatus for manufacturing super high purity nitrogen - Google Patents
Method and apparatus for manufacturing super high purity nitrogenInfo
- Publication number
- JPH05118751A JPH05118751A JP708492A JP708492A JPH05118751A JP H05118751 A JPH05118751 A JP H05118751A JP 708492 A JP708492 A JP 708492A JP 708492 A JP708492 A JP 708492A JP H05118751 A JPH05118751 A JP H05118751A
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- gas
- nitrogen
- rectification column
- separated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
- F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
- F25J3/04193—Division of the main heat exchange line in consecutive sections having different functions
- F25J3/04206—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product
- F25J3/04212—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product and simultaneously condensing vapor from a column serving as reflux within the or another column
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
- F25J3/04309—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of nitrogen
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
- F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2200/00—Processes or apparatus using separation by rectification
- F25J2200/90—Details relating to column internals, e.g. structured packing, gas or liquid distribution
- F25J2200/94—Details relating to the withdrawal point
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2205/00—Processes or apparatus using other separation and/or other processing means
- F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2215/00—Processes characterised by the type or other details of the product stream
- F25J2215/42—Nitrogen or special cases, e.g. multiple or low purity N2
- F25J2215/44—Ultra high purity nitrogen, i.e. generally less than 1 ppb impurities
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/42—Separating low boiling, i.e. more volatile components from nitrogen, e.g. He, H2, Ne
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2250/00—Details related to the use of reboiler-condensers
- F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
- F25J2250/42—One fluid being nitrogen
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Separation By Low-Temperature Treatments (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は半導体の製造工程等で使
用される、水素,ヘリウム,ネオン等の低沸点成分の含
有が少ない超高純度窒素の製造方法及びその装置であっ
て、詳しくは、複式精留塔の下部精留塔で原料空気から
精留分離された気体窒素を凝縮器で凝縮液化し、前記凝
縮器で凝縮液化された液体窒素を還流液として前記下部
精留塔頂部に導入し、前記還流液の一部を前記下部精留
塔から導出して気化し、製品窒素ガスを製造する超高純
度窒素製造方法及びその装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing ultra-high-purity nitrogen used in semiconductor manufacturing processes and containing a low boiling point component such as hydrogen, helium, or neon. The gaseous nitrogen rectified and separated from the feed air in the lower rectification column of the double rectification column is condensed and liquefied by a condenser, and the liquid nitrogen condensed and liquefied by the condenser is used as a reflux liquid at the top of the lower rectification column. The present invention relates to an ultrahigh-purity nitrogen production method and an apparatus for producing a product nitrogen gas by introducing and refluxing a part of the reflux liquid from the lower rectification column to vaporize the product.
【0002】[0002]
【従来の技術】高純度窒素製造方法及びその装置とし
て、従来、原料空気から精留分離された気体窒素を凝縮
器で凝縮するとともに、このとき凝縮液化しなかった低
沸点成分が多く含まれる未凝縮気体を排出して精留塔か
らの気体窒素中に含まれていた低沸点成分を除去した
後、その凝縮液化された低沸点成分の少ない液体窒素を
還流液として精留塔頂部に導入し、還流液として導入さ
れた液体窒素の一部を前記精留塔頂部の精留板よりも数
段下の精留板から導出して当該液体窒素中に含まれてい
た低沸点成分を精留分離して、高純度の製品窒素を製造
する技術が提案されている(例えば、実開昭64-45290公
報参照)。2. Description of the Related Art Conventionally, as a method and apparatus for producing high-purity nitrogen, gaseous nitrogen that has been rectified and separated from raw material air is condensed in a condenser, and at this time, a large amount of low-boiling components not condensed and liquefied are contained. After discharging the condensed gas to remove the low-boiling point component contained in the gaseous nitrogen from the rectification column, the condensed liquefied liquid nitrogen with a small amount of the low-boiling point component was introduced as a reflux liquid at the top of the rectification column. , A part of the liquid nitrogen introduced as a reflux liquid is discharged from a rectification plate several stages below the rectification plate at the top of the rectification column to rectify the low boiling point components contained in the liquid nitrogen. A technique for separating and producing high-purity product nitrogen has been proposed (see, for example, Japanese Utility Model Laid-Open No. 64-45290).
【0003】[0003]
【発明が解決しようとする課題】前記従来技術は、凝縮
器で凝縮液化しなかった未凝縮気体を排出すること、及
び、還流液として導入された液体窒素の一部を精留塔頂
部の精留板よりも数段下の精留板から導出することで低
沸点成分を除去して、高純度の製品窒素を製造するもの
であるが、精留塔内で低沸点成分を精留分離するにあた
って、還流液として導入された液体窒素の一部を精留塔
頂部の精留板よりも下方の精留板から導出する程、低沸
点成分の少ない製品窒素を得られる反面、高沸点成分で
ある酸素が不純物として製品窒素中に残留し易くなる欠
点があり、製品窒素の一層の高純度化を図る上でその程
度に限度があった。本発明は上記実情に鑑みてなされた
ものであって、精留塔頂部の精留板よりも数段下の精留
板から導出した液体窒素の処理工程を工夫することによ
り、製品窒素ガスの一層の高純度化を図ることができる
ようにすることを目的とする。The above prior art is to discharge uncondensed gas that has not been condensed and liquefied in the condenser, and to purify a part of the liquid nitrogen introduced as the reflux liquid at the top of the rectification column. The low boiling point component is removed by deriving it from the rectification plate several steps below the distillation plate to produce high-purity product nitrogen, but the low boiling point component is rectified and separated in the rectification column. At this time, as a part of the liquid nitrogen introduced as the reflux liquid is discharged from the rectification plate below the rectification plate at the top of the rectification column, product nitrogen with less low-boiling point components can be obtained, while it has high boiling point components. There is a drawback that some oxygen is likely to remain in the product nitrogen as an impurity, and there is a limit to the extent to further purify the product nitrogen. The present invention has been made in view of the above circumstances, by devising a treatment process of liquid nitrogen derived from the rectification plate several stages below the rectification plate at the top of the rectification column, the product nitrogen gas The purpose is to enable further purification.
【0004】[0004]
【課題を解決するための手段】上記目的を達成する為の
本発明の第1の特徴構成は、複式精留塔の下部精留塔で
原料空気から精留分離された気体窒素を凝縮器で凝縮液
化し、前記凝縮器で凝縮液化された液体窒素を還流液と
して前記下部精留塔頂部に導入し、前記還流液の一部を
前記下部精留塔から導出して製品窒素ガスを製造する超
高純度窒素製造方法であって、 A.前記凝縮器で凝縮液化しなかった未凝縮気体を排出
して前記気体窒素中に含まれていた低沸点成分を除去す
る工程 B.前記還流液として導入された液体窒素の一部を前記
下部精留塔頂部の精留板よりも数段下の精留板から導出
して当該液体窒素中に含まれていた低沸点成分を精留分
離する工程 C.前記数段下の精留板から導出した液体窒素を過冷却
して自由膨張後気液分離し、分離した気体を排出して前
記液体窒素中に含まれていた低沸点成分を除去する工程 D.前記気液分離により分離した液体窒素を気化する工
程 上記A乃至Dの工程を有する点にある。 上記目的を達成する為の本発明の第2の特徴構成は、複
式精留塔の下部精留塔で原料空気から精留分離された気
体窒素を凝縮器で凝縮液化し、前記凝縮器で凝縮液化さ
れた液体窒素を還流液として前記下部精留塔頂部に導入
し、前記還流液の一部を前記下部精留塔から導出して製
品窒素ガスを製造する超高純度窒素製造装置であって、 E.前記凝縮器で凝縮液化しなかった未凝縮気体を排出
する排出路と、 F.前記還流液として導入された液体窒素の一部を前記
下部精留塔頂部の精留板よりも数段下の精留板から導出
する導出路と、 G.前記数段下の精留板から導出した液体窒素を過冷却
して自由膨張後気液分離する気液分離器と、 H.前記気液分離器で分離した気体を排出する排出路
と、 I.前記気液分離器で分離した液体窒素を気化する気化
手段とが備えられていること 上記E乃至Iの構成にある。The first characteristic constitution of the present invention for achieving the above object is to provide a condenser for the gaseous nitrogen rectified and separated from the feed air in the lower rectification column of the double rectification column. Liquid nitrogen condensed and liquefied in the condenser is introduced as a reflux liquid to the top of the lower rectification column, and a part of the reflux liquid is discharged from the lower rectification column to produce product nitrogen gas. A method for producing ultra-high purity nitrogen, comprising: A. A step of discharging an uncondensed gas that has not been condensed and liquefied in the condenser to remove a low boiling point component contained in the gaseous nitrogen; B. A part of the liquid nitrogen introduced as the reflux liquid is discharged from a rectification plate several stages below the rectification plate at the top of the lower rectification column to refine low-boiling components contained in the liquid nitrogen. Step of separating by distillation C. A step D of supercooling the liquid nitrogen derived from the rectification plate at the lower part of the stage, performing free-expansion and gas-liquid separation, and discharging the separated gas to remove low boiling point components contained in the liquid nitrogen; . Step of Evaporating Liquid Nitrogen Separated by the Gas-Liquid Separation The step A to D is included. A second characteristic configuration of the present invention for achieving the above object is to condense and liquefy gaseous nitrogen, which has been rectified and separated from raw material air in a lower rectification column of a double rectification column, by a condenser and condense it by the condenser. An ultra-high purity nitrogen production apparatus for producing liquefied liquid nitrogen as a reflux liquid at the top of the lower rectification column and producing a product nitrogen gas by drawing a part of the reflux liquid from the lower rectification column, , E. A discharge path for discharging uncondensed gas that has not been condensed and liquefied in the condenser; A discharge path for discharging a part of the liquid nitrogen introduced as the reflux liquid from a rectification plate several stages below the rectification plate at the top of the lower rectification column; A gas-liquid separator that supercools the liquid nitrogen derived from the rectifying plate at the lower part of the stages and performs free-expansion and then gas-liquid separation; An exhaust path for exhausting the gas separated by the gas-liquid separator, and I. And a vaporizing means for vaporizing the liquid nitrogen separated by the gas-liquid separator.
【0005】[0005]
【作用】前記Aの構成により、凝縮器で凝縮液化しなか
った低沸点成分が多く含まれる未凝縮気体を排出して下
部精留塔からの気体窒素中に含まれていた低沸点成分を
除去した後、その凝縮液化された低沸点成分の少ない液
体窒素が還流液として下部精留塔頂部に導入され、前記
Bの構成により、還流液として導入された液体窒素の一
部を下部精留塔頂部の精留板よりも数段下の精留板から
導出して当該液体窒素中に含まれていた低沸点成分が精
留分離され、前記Cの構成により、気化し易い低沸点成
分を多く含む分離気体を排出して精留板で精留分離でき
なかった低沸点成分が更に除去されて、従来に比べて高
純度の液体窒素が製出され、前記Dの構成により、その
高純度の液体窒素がガス化される。又、前記E乃至Iの
構成によっても、凝縮器で凝縮液化しなかった低沸点成
分が多く含まれる未凝縮気体を排出して下部精留塔から
の気体窒素中に含まれていた低沸点成分を除去した後、
その凝縮液化された低沸点成分の少ない液体窒素が還流
液として下部精留塔頂部に導入され、還流液として導入
された液体窒素の一部を下部精留塔頂部の精留板よりも
数段下の精留板から導出して当該液体窒素中に含まれて
いた低沸点成分が精留分離され、更に、気液分離によ
り、気化し易い低沸点成分を多く含む分離気体を排出し
て精留板で精留分離できなかった低沸点成分が更に除去
されて、従来に比べて高純度の液体窒素が製出され、そ
の高純度の液体窒素がガス化される。With the structure of A, the uncondensed gas containing a large amount of the low-boiling components that have not been condensed and liquefied in the condenser is discharged to remove the low-boiling components contained in the gaseous nitrogen from the lower rectification column. After that, the condensed and liquefied liquid nitrogen having a low amount of low boiling point components is introduced as a reflux liquid to the top of the lower rectification column, and part of the liquid nitrogen introduced as the reflux liquid is partly converted into the lower rectification column by the constitution of B. The low-boiling-point components contained in the liquid nitrogen derived from the rectification plate several steps below the top rectification plate are rectified and separated, and due to the constitution of C, the low-boiling-point components that are easily vaporized are increased. By discharging the separated gas containing it, low-boiling components that could not be rectified and separated by the rectification plate are further removed, and liquid nitrogen of higher purity than the conventional one is produced. Liquid nitrogen is gasified. Further, also by the constitutions of E to I, the low-boiling component contained in the gaseous nitrogen from the lower rectification column is discharged by discharging the uncondensed gas containing a large amount of the low-boiling component not condensed and liquefied in the condenser. After removing
The condensed and liquefied liquid nitrogen with less low-boiling point components is introduced as a reflux liquid to the top of the lower rectification column, and a part of the liquid nitrogen introduced as the reflux liquid is introduced in several stages than the rectification plate at the top of the lower rectification column. The low-boiling components contained in the liquid nitrogen derived from the lower rectification plate are rectified and separated.Furthermore, by gas-liquid separation, the separated gas containing many low-boiling components that are easily vaporized is discharged and purified. The low boiling point components that could not be rectified and separated by the distillation plate are further removed to produce liquid nitrogen of higher purity than in the past, and the liquid nitrogen of high purity is gasified.
【0006】[0006]
【発明の効果】低沸点成分を精留分離した後の液体窒素
の一部を高沸点成分である酸素の残留が少ない状態で下
部精留塔頂部の精留板よりも数段下の精留板から導出し
て、精留分離しきれなかった低沸点成分を、気液分離で
分離した気体を排出することで除去でき、製品窒素ガス
の一層の高純度化を図ることができる。EFFECTS OF THE INVENTION A portion of liquid nitrogen after rectifying and separating low-boiling components is rectified several stages below the rectification plate at the top of the lower rectification column with a small amount of residual high-boiling oxygen. The low-boiling point components that have been discharged from the plate and could not be rectified and separated can be removed by discharging the gas separated by gas-liquid separation, and the product nitrogen gas can be further purified.
【0007】[0007]
【実施例】図1,図2は本発明による超高純度窒素製造
方法及びその装置の実施例を示すフローダイヤグラム
で、原料空気を複式精留塔の下部精留塔である中圧精留
塔5で精留して、精留分離した気体窒素を複式精留塔の
上部精留塔である低圧精留塔6底部に設けた凝縮器15
で凝縮液化し、凝縮液化された液体窒素を還流液として
再び中圧精留塔5頂部に導入して、この還流液の一部を
中圧精留塔5頂部の精留板よりも数段下の精留板から導
出し、更に、過冷却器9で過冷却して自由膨張後気液分
離器10で気液分離して超高純度の液体窒素を分離し、
この超高純度液体窒素の一部を気化手段としての熱交換
器11,4で気化して製品窒素ガスとして導出するもの
である。1 and 2 are flow diagrams showing an embodiment of an ultrahigh-purity nitrogen production method and apparatus according to the present invention, in which raw air is a medium-pressure rectification column which is a lower rectification column of a double rectification column. The condenser 15 provided at the bottom of the low pressure rectification column 6 which is the upper rectification column of the double rectification column
Is condensed and liquefied in, and the condensed and liquefied liquid nitrogen is again introduced into the top of the medium-pressure rectification column 5 as a reflux liquid, and a part of this reflux liquid is several stages higher than the rectification plate at the top of the medium-pressure rectification column 5. Derived from the lower rectification plate, further supercooled by a supercooler 9 and free-expanded, and then gas-liquid separated by a gas-liquid separator 10 to separate ultra-high-purity liquid nitrogen,
Part of this ultra-high-purity liquid nitrogen is vaporized by the heat exchangers 11 and 4 as vaporization means and is discharged as product nitrogen gas.
【0008】前記原料空気は空気瀘過器1を通過して空
気中の塵埃が除去され、配管P1で空気圧縮機2に導かれ
て圧力約5Kg/cm2Gに圧縮され、配管P2に導かれて冷却
除炭乾燥ユニット3で冷却及び炭酸ガスと水分の除去が
行われて、配管P3で熱交換器4に導入される。熱交換器
4に導入された原料空気は、低圧精留塔6頂部から配管
P19 、過冷却器9、配管P20 を通って熱交換器4に導入
される高純度窒素ガスと、低圧精留塔6からの廃ガスを
過冷却器7に導入する廃ガス配管P12 に気液分離器10
からの廃ガスを導出する廃ガス配管P31,P32 を接続し
て、過冷却器7から配管P33 を通って熱交換器4に導入
される低圧精留塔6及び気液分離器10からの廃ガス
と、低圧精留塔6から配管P21 を通って熱交換器4に導
入される酸素ガスと、配管P42 を通って熱交換器4に導
入される後述の超高純度窒素ガスと、中圧精留塔5頂部
から配管P22 で導出された中圧高純度窒素ガスを分流さ
せて配管P44 で熱交換器4に導入される中圧高純度窒素
ガスとで熱交換して液化点近くにまで冷却され、配管P4
で中圧精留塔5底部に導入され、この中圧精留塔5内の
精留部A,B,Cで精留されて頂部に窒素ガス及び液体
窒素、底部に酸素リッチ液体が製出する。The raw material air passes through the air filter 1 to remove dust in the air, is guided to the air compressor 2 by the pipe P1, is compressed to a pressure of about 5 kg / cm 2 G, and is guided to the pipe P2. After cooling, the cooling and decarburizing / drying unit 3 cools and removes carbon dioxide gas and water, and introduces it into the heat exchanger 4 through the pipe P3. The raw material air introduced into the heat exchanger 4 is piped from the top of the low pressure rectification column 6.
High-purity nitrogen gas introduced into the heat exchanger 4 through P19, the supercooler 9, and the pipe P20, and a waste gas pipe P12 that introduces the waste gas from the low-pressure rectification column 6 into the supercooler 7 are gas-liquid. Separator 10
Waste gas from the low pressure rectification column 6 and the gas-liquid separator 10 which are introduced into the heat exchanger 4 through the pipe P33 from the subcooler 7 by connecting the waste gas pipes P31 and P32 for discharging the waste gas from the Gas, oxygen gas introduced from the low-pressure rectification column 6 into the heat exchanger 4 through the pipe P21, ultra-high-purity nitrogen gas described later introduced into the heat exchanger 4 through the pipe P42, and medium pressure The medium-pressure high-purity nitrogen gas derived from the top of the rectification column 5 through the pipe P22 is diverted and heat-exchanged with the medium-pressure high-purity nitrogen gas introduced into the heat exchanger 4 through the pipe P44 to near the liquefaction point. Cooled and piping P4
Is introduced into the bottom of the medium pressure rectification column 5 and is rectified in the rectification sections A, B and C in the medium pressure rectification column 5 to produce nitrogen gas and liquid nitrogen at the top and an oxygen rich liquid at the bottom. To do.
【0009】中圧精留塔5の底部に溜まった酸素リッチ
液体は、切換え使用される液体空気瀘過器8a,8b に配管
P5で導入して酸素リッチ液体中に濃縮された炭化水素分
が除去されたあと、配管P6で過冷却器7に導入されて低
圧精留塔6及び気液分離器10からの廃ガスと熱交換し
て過冷却され、配管P7に設けた膨張弁V1で自由膨張させ
て冷却され、配管P8で低圧精留塔6の上下中央部に導入
される。中圧精留塔5の上下中央部にできる液体窒素は
液溜R3から配管P9で過冷却器7に導入され、低圧精留塔
6及び気液分離器10からの廃ガスと熱交換して過冷却
され、配管P10 で膨張弁V2に導かれて自由膨張させて更
に冷却され、配管P11 で低圧精留塔6の上部に導入され
る。The oxygen-rich liquid accumulated at the bottom of the medium-pressure rectification column 5 is piped to the liquid-air filters 8a and 8b used for switching.
After removing the hydrocarbon content introduced in P5 and concentrated in the oxygen-rich liquid, it is introduced into the supercooler 7 through the pipe P6 and the waste gas and heat from the low pressure rectification column 6 and the gas-liquid separator 10 are removed. It is exchanged and supercooled, is freely expanded by an expansion valve V1 provided in a pipe P7, is cooled, and is introduced into the upper and lower central portions of the low pressure rectification column 6 through a pipe P8. Liquid nitrogen formed in the upper and lower central portions of the medium pressure rectification column 5 is introduced from the liquid reservoir R3 into the subcooler 7 through the pipe P9 and exchanges heat with the waste gas from the low pressure rectification column 6 and the gas-liquid separator 10. It is supercooled, guided to the expansion valve V2 through the pipe P10, freely expanded and further cooled, and introduced into the upper part of the low pressure rectification column 6 through the pipe P11.
【0010】原料空気中の低沸点成分(ヘリウム(H
e),水素(H2),ネオン(Ne))は一般に、ヘリ
ウムが約 5,000容積PPB(VPPB) 、水素が約 500容積PPB
(VPPB)、ネオンが約15,000容積PPB(VPPB) であるが、中
圧精留塔5の底部に溜まった酸素リッチ液体中には、ヘ
リウムが約20VPPB、水素が約10VPPB、ネオンが約 400VP
PB溶け込み、残りが中圧精留塔5頂部の窒素ガス中に濃
縮される。そして、中圧精留塔5頂部に製出された窒素
ガスは、精留塔内の配管P35 で低圧精留塔6底部に設け
た凝縮器15に導入されて、低圧精留塔6の液体酸素と
の熱交換で凝縮液化される。このとき、窒素ガスと一緒
に凝縮器15に導入された低沸点成分の大部分は液化さ
れずにガス状で凝縮器15の下部から排出路としての配
管P58 を通り、合計約1,000,000VPPB 乃至20,000,000VP
PB (約 0.1乃至 2.0容積% )の低沸点成分を含む未凝縮
窒素ガスとして弁V8を通って排気される。Low boiling point components (helium (H
e), hydrogen (H 2 ), neon (Ne)) are generally about 5,000 volume PPB (VPPB) for helium and about 500 volume PPB for hydrogen.
(VPPB) and neon are about 15,000 volume PPB (VPPB), but in the oxygen-rich liquid accumulated at the bottom of the medium-pressure rectification column 5, helium is about 20 VPPB, hydrogen is about 10 VPPB, and neon is about 400 VP.
PB is dissolved, and the rest is concentrated in nitrogen gas at the top of the medium pressure rectification column 5. Then, the nitrogen gas produced at the top of the medium pressure rectification column 5 is introduced into the condenser 15 provided at the bottom of the low pressure rectification column 6 through the pipe P35 in the rectification column, and the liquid of the low pressure rectification column 6 is discharged. It is condensed and liquefied by heat exchange with oxygen. At this time, most of the low boiling point components introduced into the condenser 15 together with the nitrogen gas are not liquefied and are in a gaseous state from the lower part of the condenser 15 through the pipe P58 as an exhaust passage, and the total amount is about 1,000,000 VPPB to 20,000,000. VP
Exhausted through valve V8 as uncondensed nitrogen gas containing low boiling components of PB (about 0.1-2.0% by volume).
【0011】凝縮器15で凝縮液化された液体窒素は還
流液として配管P36 で中圧精留塔5の液溜R1に導入され
るのであるが、当該液体窒素中には合計約200,000VPPB
の低沸点成分を含んでいるので、この低沸点成分を更に
少なくする為に中圧精留塔5頂部に設けられている数段
の精留板からなる精留部Cで精留し、合計約350VPPBの
低沸点成分を含む液体窒素として精留部Cの下部に設け
た液溜R2に溜める。液溜R2から導出路としての配管P13
で導出された液体窒素は、過冷却器9で低圧精留塔6頂
部から配管P19 で導出されてきた高純度窒素ガス(低沸
点成分 合計約1,000VPPB )と熱交換して過冷却され、
配管P14 で取り出して膨張弁V4で自由膨張させて更に温
度を下げ、一部が気化した気液混合状態の液体窒素を配
管P15 で気液分離器10に導入する。気液分離器10に
導入された気液混合状態の液体窒素は気液分離され、分
離された窒素ガスには合計約3,000VPPB の低沸点成分を
含んでいるので、排出路としての配管P31 に導入して弁
V5で圧力を調節し、配管P32 から排出する。この結果、
気液分離器10で分離された液体窒素は、合計約10VPPB
の低沸点成分(低沸点成分がヘリウムと水素である場合
は、合計約0.3VPPB )が含まれるに過ぎない超高純度に
精製されたものとなっている。The liquid nitrogen condensed and liquefied in the condenser 15 is introduced as a reflux liquid into the liquid reservoir R1 of the medium-pressure rectification column 5 through a pipe P36, and the total amount of the liquid nitrogen is approximately 200,000 VPPB.
Since it contains the low-boiling point component of the above, in order to further reduce this low-boiling point component, it is rectified in the rectification section C consisting of several rectification plates provided at the top of the medium pressure rectification column 5, and the total The liquid nitrogen containing a low boiling point component of about 350 VPPB is stored in a liquid reservoir R2 provided below the rectification section C. Piping P13 as outlet from liquid reservoir R2
The liquid nitrogen derived in 1. is supercooled in the supercooler 9 by exchanging heat with the high-purity nitrogen gas (low-boiling point components total about 1,000 VPPB) derived from the top of the low-pressure rectification column 6 through the pipe P19,
Liquid nitrogen in a gas-liquid mixed state, partially vaporized, is introduced into the gas-liquid separator 10 by taking it out through the pipe P14 and freely expanding it with the expansion valve V4 to further lower the temperature. The liquid-nitrogen in the gas-liquid mixed state introduced into the gas-liquid separator 10 is gas-liquid separated, and the separated nitrogen gas contains a low boiling point component of about 3,000 VPPB in total. Introduce valve
Adjust the pressure with V5 and discharge from pipe P32. As a result,
The liquid nitrogen separated by the gas-liquid separator 10 is about 10VPPB in total.
The low boiling point component (when the low boiling point components are helium and hydrogen, the total amount is about 0.3VPPB) is purified to an ultra-high purity.
【0012】気液分離器10で分離される液体窒素の量
が略一定になるよう、気液分離器10の液面制御器 LIC
と膨張弁V4とが連係され、分離された超高純度の液体窒
素は、その一部が流量制御器付弁V6で流量制御される配
管P16,P41 で熱交換器11に導出されて、中圧精留塔5
頂部から配管P22 で導出された中圧高純度窒素ガスを冷
却液化し、更に、配管P42 で熱交換器4に導入されて原
料空気との熱交換で気化されて、超高純度の製品窒素ガ
スとして配管P43 で貯槽(図示せず)に貯留される。
尚、熱交換器11で冷却液化された高純度液体窒素は、
配管P45 で中圧精留塔5頂部に還流液として導入され
る。また、気液分離器10で分離された超高純度液体窒
素の残りは、流量制御器付弁V7で流量制御される配管P1
7,P18 で一定の流量に制御して低圧精留塔6頂部に導入
され、低圧精留塔6の精留部D,E,F,Gの還流液と
して低圧精留塔6を上昇するガスを精留する。A liquid level controller LIC of the gas-liquid separator 10 so that the amount of liquid nitrogen separated by the gas-liquid separator 10 becomes substantially constant.
The ultrahigh-purity liquid nitrogen that has been separated by linking the expansion valve V4 with the expansion valve V4 is partially discharged to the heat exchanger 11 through the pipes P16 and P41 whose flow rate is controlled by the valve V6 with a flow rate controller. Pressure rectification tower 5
The medium-pressure high-purity nitrogen gas derived from the top through pipe P22 is cooled and liquefied, and is further introduced into the heat exchanger 4 through pipe P42 and vaporized by heat exchange with the raw air, resulting in ultra-high-purity product nitrogen gas. It is stored in a storage tank (not shown) through pipe P43.
The high-purity liquid nitrogen liquefied by the heat exchanger 11 is
It is introduced as a reflux liquid at the top of the medium pressure rectification column 5 through a pipe P45. Further, the remainder of the ultra-high purity liquid nitrogen separated by the gas-liquid separator 10 is a pipe P1 whose flow rate is controlled by a valve V7 with a flow rate controller.
Gas that is introduced to the top of the low-pressure rectification column 6 with a constant flow rate controlled by 7, P18 and rises in the low-pressure rectification column 6 as the reflux liquid of the rectification sections D, E, F, G of the low-pressure rectification column 6. Rectify.
【0013】配管P19 で低圧精留塔6頂部から過冷却器
9に導かれた高純度窒素ガスは、配管P20,熱交換器4を
経て、常温低圧の高純度窒素ガスとなり、配管P52 で高
純度の製品窒素ガスとして取り出される。低圧精留塔6
はその底部で中圧精留塔5からの熱を授受して精留部
D,E,F,Gで精留し、頂部に高純度窒素ガスを、下
部に液体酸素を製出する。配管P44 で熱交換器4に導入
された中圧高純度窒素ガスは、膨張機13で断熱膨張さ
れて冷却され、配管P46 で低圧精留塔6の精留部Fの下
部に導入される。また、低圧精留塔6の下部に製出した
酸素ガスは、配管P21,熱交換器4,配管P55 を経て取り
出される。The high-purity nitrogen gas introduced from the top of the low-pressure rectification column 6 to the subcooler 9 through the pipe P19 becomes high-purity nitrogen gas at room temperature and low pressure through the pipe P20 and the heat exchanger 4, and the high-purity nitrogen gas through the pipe P52. It is taken as pure product nitrogen gas. Low pressure rectification column 6
Heat is transferred from the medium-pressure rectification column 5 at its bottom to rectify at the rectification sections D, E, F, G, and produces high-purity nitrogen gas at the top and liquid oxygen at the bottom. The medium-pressure high-purity nitrogen gas introduced into the heat exchanger 4 through the pipe P44 is adiabatically expanded by the expander 13 and cooled, and introduced into the lower portion of the rectification section F of the low-pressure rectification column 6 through the pipe P46. The oxygen gas produced in the lower part of the low pressure rectification column 6 is taken out through the pipe P21, the heat exchanger 4 and the pipe P55.
【0014】過冷却器7から配管P33 を通って熱交換器
4に導入された低圧精留塔6及び気液分離器10からの
廃ガスは、配管P56 から排出されるとともに、その一部
は配管P34 で冷却徐炭乾燥ユニット3に供給されてその
再生に使用された後、配管P57 から排出される。Waste gas from the low-pressure rectification column 6 and the gas-liquid separator 10 introduced from the subcooler 7 to the heat exchanger 4 through the pipe P33 is discharged from the pipe P56, and a part of the waste gas is discharged. It is supplied to the cooling and slow coal drying unit 3 through the pipe P34, used for its regeneration, and then discharged through the pipe P57.
【0015】〔別実施例〕実施例において、配管P35 か
らの窒素ガスを窒素凝縮器15で冷却してから別途設け
た気液分離器に導いて凝縮液化した液体窒素と凝縮液化
しなかった未凝縮窒素ガスとに気液分離し、その液体窒
素を配管P36 で中圧精留塔5の液溜R1に導入するととも
に、未凝縮窒素ガスを配管P58 で排出しても良い。[Other Example] In the example, the nitrogen gas from the pipe P35 was cooled by the nitrogen condenser 15 and then introduced into a separately provided gas-liquid separator to condense and liquefy liquid nitrogen, which was not condensed and liquefied. It is also possible to separate the condensed nitrogen gas into gas and liquid, introduce the liquid nitrogen into the liquid reservoir R1 of the medium-pressure rectification column 5 through the pipe P36, and discharge the uncondensed nitrogen gas through the pipe P58.
【0016】尚、特許請求の範囲の項に図面との対照を
便利にするために符号を記すが、該記入により本発明は
添付図面の構成に限定されるものではない。It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.
【図1】超高純度窒素製造方法及びその装置を示すフロ
ーダイヤグラムFIG. 1 is a flow diagram showing a method and an apparatus for producing ultra-high purity nitrogen.
【図2】超高純度窒素製造方法及びその装置を示すフロ
ーダイヤグラムFIG. 2 is a flow diagram showing an ultrahigh-purity nitrogen production method and apparatus.
4 気化手段 5 下部精留塔 10 気液分離器 11 気化手段 15 凝縮器 P13 導出路 P31 排出路 P58 排出路 4 vaporization means 5 lower rectification column 10 gas-liquid separator 11 vaporization means 15 condenser P13 outlet path P31 discharge path P58 discharge path
Claims (2)
気から精留分離された気体窒素を凝縮器(15)で凝縮
液化し、前記凝縮器(15)で凝縮液化された液体窒素
を還流液として前記下部精留塔(5)頂部に導入し、前
記還流液の一部を前記下部精留塔(5)から導出して気
化し、製品窒素ガスを製造する高純度窒素製造方法であ
って、前記凝縮器(15)で凝縮液化しなかった未凝縮
気体を排出して前記気体窒素中に含まれていた低沸点成
分を除去する工程と、前記還流液として導入された液体
窒素の一部を前記下部精留塔(5)頂部の精留板よりも
数段下の精留板から導出して当該液体窒素中に含まれて
いた低沸点成分を精留分離する工程と、前記数段下の精
留板から導出した液体窒素を過冷却して自由膨張後気液
分離し、分離した気体を排出して前記液体窒素中に含ま
れていた低沸点成分を除去する工程と、前記気液分離に
より分離した液体窒素を気化する工程とを有する超高純
度窒素製造方法。1. Gaseous nitrogen which has been rectified and separated from raw material air in a lower rectification column (5) of a double rectification column is condensed and liquefied in a condenser (15) and condensed and liquefied in the condenser (15). High-purity nitrogen for producing product nitrogen gas by introducing liquid nitrogen as a reflux liquid into the top of the lower rectification column (5) and discharging a part of the reflux liquid from the lower rectification column (5) to vaporize the product nitrogen gas. A manufacturing method, a step of discharging an uncondensed gas that has not been condensed and liquefied in the condenser (15) to remove a low boiling point component contained in the gaseous nitrogen, and a step of being introduced as the reflux liquid. A step of deriving a part of the liquid nitrogen from a rectification plate several stages below the rectification plate at the top of the lower rectification column (5) to rectify and separate low-boiling components contained in the liquid nitrogen. And the liquid nitrogen derived from the rectification plate below the above several stages was supercooled and free-expanded to be gas-liquid separated. A method for producing ultra-high purity nitrogen, which comprises a step of discharging a body to remove low-boiling components contained in the liquid nitrogen, and a step of vaporizing the liquid nitrogen separated by the gas-liquid separation.
気から精留分離された気体窒素を凝縮器(15)で凝縮
液化し、前記凝縮器(15)で凝縮液化された液体窒素
を還流液として前記下部精留塔(5)頂部に導入し、前
記還流液の一部を前記下部精留塔(5)から導出して気
化し、製品窒素ガスを製造する高純度窒素製造装置であ
って、前記凝縮器(15)で凝縮液化しなかった未凝縮
気体を排出する排出路(P58 )と、前記還流液として導
入された液体窒素の一部を前記下部精留塔(5)頂部の
精留板よりも数段下の精留板から導出する導出路(P1
3)と、前記数段下の精留板から導出した液体窒素を過
冷却して自由膨張後気液分離する気液分離器(10)
と、前記気液分離器(10)で分離した気体を排出する
排出路(P31 )と、前記気液分離器(10)で分離した
液体窒素を気化する気化手段(11),(4)とが備え
られている超高純度窒素製造装置。2. The gaseous nitrogen rectified and separated from the raw material air in the lower rectification column (5) of the double rectification column is condensed and liquefied in the condenser (15) and condensed and liquefied in the condenser (15). High-purity nitrogen for producing product nitrogen gas by introducing liquid nitrogen as a reflux liquid into the top of the lower rectification column (5) and discharging a part of the reflux liquid from the lower rectification column (5) to vaporize the product nitrogen gas. In the manufacturing apparatus, a discharge passage (P58) for discharging uncondensed gas that has not been condensed and liquefied in the condenser (15) and a part of the liquid nitrogen introduced as the reflux liquid are used in the lower rectification column ( 5) Derivation path leading from the rectification plate several steps below the top rectification plate (P1
3), and a gas-liquid separator (10) for supercooling the liquid nitrogen derived from the rectification plate at the lower stage and free-expanding to separate gas and liquid.
A discharge path (P31) for discharging the gas separated by the gas-liquid separator (10), and vaporizing means (11), (4) for vaporizing the liquid nitrogen separated by the gas-liquid separator (10). Ultra-high purity nitrogen production equipment equipped with.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP708492A JPH05118751A (en) | 1991-09-06 | 1992-01-20 | Method and apparatus for manufacturing super high purity nitrogen |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP22631791 | 1991-09-06 | ||
JP3-226317 | 1991-09-06 | ||
JP708492A JPH05118751A (en) | 1991-09-06 | 1992-01-20 | Method and apparatus for manufacturing super high purity nitrogen |
Publications (1)
Publication Number | Publication Date |
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JPH05118751A true JPH05118751A (en) | 1993-05-14 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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JP708492A Pending JPH05118751A (en) | 1991-09-06 | 1992-01-20 | Method and apparatus for manufacturing super high purity nitrogen |
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JP (1) | JPH05118751A (en) |
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1992
- 1992-01-20 JP JP708492A patent/JPH05118751A/en active Pending
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